Shimano PD R8000 pedals, broken?

[Yuxi]

My friend has bought some secondhand PD R8000 pedals.
The adjuster clicks when it is turned but the indicator stays in the upper position all the time, even when the screw is turned to one extreme or the other.
Neither of us have used clip in pedals before but it seems very difficult to disengage the shoe.

Are the pedals broken, can they be fixed?

Thanks